Telegraphy.



Patented Mar121, 1916.

4 SHEETS-SHEET l.

NVENTOR ISA ORNEY 1 E. KEEN.

TELEGRABHY.

" i APPLIPATION HLED NOV. 6, 1908- 1, 176,147. Patented Mar. 21,1916,

.1 4 SHEETS-SHEET 2.

3 4,014 9m ATTORNEY E.KEN. TELEGRAPHY.

APPLICATION FILED NOV. 6,1908.

Patented.11fin 21,1916.

' 4 SHEETSSHEET 3- E. KEEN.

TELEGRAPHY.

APPLICATION FILED NOV. 6, 1908.

Patented Mar. 21, 1916.

4 SHEETS-SHEET 4- TEsPATEN'r OFFICE.

nnro'r KEEN, 01 NEW Yonx, n. Y., nssrenon 'ro' 'rnnuemvuma'conrnnx, A I conronarron or NEW YORK. I

TELEGRAPH.

Specification amen new ratentea- Mar. 21, 1916.

Application filed November 6, 1908. Serial No. 461,885.

and comprises certain improvements in an apparatus for this purpose and particularly adapted for the carrying out of the novel process of my invention for transmission of pictures electrically.

In my process I propose to use ahalf-tone' cut or negative of the picture, or its.equiva-.

lent, from which, by means of-suitable api I paratus, I produce a series of electrical 1mpulses proportioned .to the size of the several dots composing the half-tone, either by making and breaking the electrical circuit at every dot, or by varying the current strength in the circuit, the former method being preferred. At the receiving station, which may electrical circuit, suitable mechanism controlled by the electrical impulses is provided for reproducing the picture or half-tone. This is preferably accomplished by producing a series ofdots located in the same relative positions as the dots of the original half-tone and through the electrical impulses proportioned in area to the sizes of corresponding original dots. A half-tone picture of exactly the appearance of the.

original half-tone is thus produced.

I have illustrated indetail certain specified sending and receiving apparatus by but I as I may use any desired sending apparatus which...

which my process may be carried out, do not desire to be limited thereto,

will produce a varying electrical impulse or series of impulses proportioned to the tones of a picture with my lmproved receiving whereby certain of my process bodying certain of my is a detailed be located at any point in the- .I do not claim my improved processor processes in th1s application, neither do I claim the apparatus for performing such.

processes in its broadest aspects. Such processes and apparatus are claimed broadly in my application Serial Number 548,047 filed March 8th, 1910. In the present case the invention claimed. relates to' certain features of construction not illustrated or not claimed in sald application, but which are applicable to the carrying out of the inventionstherem broadly set forth and claimed,

some of the features, however, being also useful in other relations. In the accompanying drawings Figure 1 is'a plan view of asending apparatus emimprovements, parts of the apparatus bein shown in section; Fig. 2 is a plan view 0 a receiving apparatus; Fig. 3 is a transverse section of the receiving apparatus shown in Fig. 2; Fig. 4 side elevation showing gearing for operating the diaphragm mechanism; Fig. 5 is a detailed view of the diaphragm mechanism of the-receiving apparatus; Fig. 6 isa detailed view of my selenium sending element; Fig. 7 is a front elevation of the movable screen forming part of the sending mechanism; Fi 8 is a horizontal section element, show ng thelatter in plan; Fig. 9

phragms having graduated holes therein; Fig. 10 is a view illustrating an arrangement of diaphragms with a shutter for controlling the passage of light in the aperture between the diaphragms; and Fig. 11 is a diagrammatic view illustrating the arrangement 'of the mirror so as to produce a p0S1-- detail, the

tive instead of a negative record.

.Beferring to the. drawmgs 1n numeral 1 deslgnates the transparent hollow cylinder of the transmitting apparatus in which is a mercury tube light 2, or any other suitable sourc'e of illumination. Suitable connections for supplying electricity to this light may cated at 3, 3. about its axis by means of a'motor 4 throughbe used, such, as those indi-- The cylinder 1 is rotated through the casmg for the selenium sending" a series of gears 5 and 6. Simultaneously with this rotation a carriage 9is, moved parallel to the axis of the. cylinder 'lby means of a screw 8 rotated from the motor .4 in

- any suitable manner,

7 with the screw 8 by I contactsso that the ring electrical connection therewith by means of the pencil of light I between the brushes 24 and 25.

w front of the chamber .23 carried mounted on the rear face carried. thereby 9 is fed longitudinally witha gear 6. Guide bars 10 serve to support the carriage 9. The carriage 9 engages means of a split nut 11, which may be opened and closed by a screw 12 to permit adjustment of the carriage 9. The pitch of the screw 8 and the gears 6 and 7 are so proportioned that the carriage 9 will move longitudinally a distance equal to the distance between two of the rows of dots forming the half-tone carried by the cylinder l' and designated by the numeral 1,

1 makes a single revolu- While the cylinder tion. The dots forming'the half-tone will thus be brought successively opposite the aperture 30 in the screen 3O forming the by the carriage 9. The position of the, chamber 23 which is pivoted to the carriage at 27, may be adjusted by means of a screw 28. Back of the aperture 30 in thev chamber is a lens 31 which difluses thelight coming .through the aperture throughout the chamber. In the rear part of the chamber is a fixed diaphragm 22 provided with an aperture 22. In the rear of the chamber back of this diaphragm is mounted a disk 20 car-,

ried by a rotatable shaft 17 and bearing upon its front face a ring 19 of selenium wire or its equivalent. The disk 20 and the selenium ring 19 are so positioned that a portion of the ring will always be exposed back of theaperture 22*. A pair of conducting brushes or contacts 24 and 25 are of the diaphragm 22,-the disk 20 being forced toward these 19 will be held in a spring 21. The shaft 17 and the disk 20 are rotated slowly by any suitable means suchas the gear 16 on the end of shaft 17 engaged by the gear 15 mounted on the shaft 14. On the other end of shaft 14 is a pinion 13engaging with rack-teeth 10 cut in the face of guide bar 10. As will be obvious, when the carriage by the screw 8, the pinion 13 which moves therewith will be rotated through its engagement with the fixed rack-teeth 10.

The operation of this lows: The. light through the lamp 2 passes through the transparent cylinder 1, and through the transparent portions of the halftone negative 1; as the successive transparent portions or dots on this negative register with the aperture 30 in the screen 30, will pass through the aperture and be diffused by the lens 31 into the chamber 23 from which a portion ofit will pass through the aperture'22 'up0n that portion of the ring of selenium 19 exposed The, effect of the exposure of the substance selenium as by a gear 7 meshing 35 supplies" electricity mechanism is'as' fol-- to light is, as is well known, to greatly increase its conductivity. Selenium when not exposed to light is a very poor electrical conductor. The circuit 26 which includes the brushes 24 and 25 is closed through that .portion of the selenium ring exposed between the edges of the brushes. 7 The length of the exposure of this portion of the selenium to the light depends on the size of thejtransparent dot on the half-tone negalonger exposed to the beam of light, iS"Ob-. viated. The circuit 26 is preferablya local circuit and operates the relay 32 which closes the main line circuit 33.- A circuit,

being aswit'ch for controlling the same.

Referring now to the receiving'machine shown in Figs. 2"and v which is opened and closed by the relay 32 in the manner described, once for every dot ofi the half-tone negative, contains at the receiving end a relay-34 which opens and closes a local circuit '35. In this circuit.

35 is an electro-magnet .60, the. armature 59 of which is preferably made in the form 'of a bell-crank and bea'rs on the free arm thereof amirror 36. The -spring 61 serves to draw the armature away from the magnet when the circuit is broken. of light adapted to be reflected by the mirror 36 and directed by the lattertoward the picture reproducing mechanism. This mechanism comprises. a light-proof casing 58 inclosing a cylinder 54, to which is secured a sensitized film 38. A key 64 fitted in a slot in the cylinder may be used for the latter purpose, the edges of the film being wedged into the slotbeneath the key. -'The cylinder 54 is mounted upon a shaft 53, one end of which is screw-threaded as shown at 55, and

rotates in a screw-threaded bearing or nut 56. The other end of the shaft is slotted as shown at 56 and passes through the nave of the gear 52 which, is provided with a feather sliding in the slot. The gear 52 is driven through a gear 49 and pinion 50 from a mo tor 51 which receives current from anysuitable source, a from controlling switch. The casing-58 is provided with an aperture 58 in the same horizontal plane as the axis of the cylinder 54, and line with the mirror 36. The opening to this aperture is controlled by a shutter or diaphragm mech nism, of sucha. na-

for rotating the disk 20 to the motor 4, 34'

3, the main circuit 33 37 is a source the mains 35. 57 is a 60 1 scribed; this in turn closes the local circuit ture that .a light opening will be formed a which continually passes through a cycle increasmg from zero or a Opening to a maximum, and. then decreasing. As shown, this shutter mechanism comprises a series of four diaphragms 39. Diaphragm D is fixed, while diaphragms A, ,B and C are mounted on shaft/S40 adapted to be rotated by gearing 41 and 42. Diaphragms A and B are mounted on their res ective shafts with an equal eccentricity, while diaphragm C has as shown in the particular embodiment of my invention illustrated,

double the eccentricity of A and B. The

gear 42' which drives the diaphragms is mounted on a. shaft 44' which is driven through screw gearing 43, and 45 from a transverse shaft 46. The shaft46 is in turn driven through pinion 65', gear 48, pinion 66 from gear 49 which is driven, as has already been described, from the pinion 50 of the motor 51. 62 and 63 are lenses for concentrating the light reflected by the mirror 36 upon the sensitized surface 38. The motors 4 of the sending apparatus and 51 of the receiving apparatus are arranged to drive the cylinders 1 and 54 'atidentical angular velocities. Any suitable means for synchronizing these motors may be used, as for instance, they may be synchronous alternating current motors driven from the same alternating current circuit.

The operation of the reproducing mechanism is as follows: The cylinder 54 carrying the film 38 being rotated by the motor 51 at an angular velocity equal to that at which the cylinder 1 is rotated, revolves about its axis and is also moved in an axial direction by the action of the screw 55 in the nut 56. The pitch of the screw 55 is so proportioned that the ratio of the axial velocity to the circumference of the drum is the same as the ratio of the velocity of the carriage 9 to the circumference of the cylinder 1. The gearing by which the shutter mechanism'39 V is operated is so proportioned that the diaphragms A, B and C will make one revolution while a portion of the sensitized surface38 equal in width-to the width of the maximum dot which is to form reproduced half-tone passes the light aperture. If now it'be supposed that a half-tone negative is placed about the cylinder 1, and adjusted so that the first transparent dot in the first column of dots forming this negative registers with the aperture 30*, the light passing through this dot and through the aperture" acts upon the exposed portion of the seleqnium ring, closes the local circuit and closes the main circuit .inthe manner already dea at the receiving station and turns the ceive a beam of light from the fsource 37.

mirror 36 to such a position that it will re through the lens 62, the aperture 58', and

whatever opening there is between diaphragms A, B, C andD, and finally through the lens 63 upon the sensitized surface 38.

When the apparatus'starts, the diaphragms A, B and C are turned .to such, a posltion that they almost if not entirely shut olf light passing through the aperture 58, the diaphragms gradually separating to expose a largerand larger portion of the sensitized surface. If the dot at the sending appara- ,tus is small, the circuit will break when but a small opening has been found between the diaphragms; so that a dot of corresponding size will be recorded. As will be apparent in thesending half-tone, the centers of successive dots are equal distances apart regardless of the size of the dot, so that the impulse corresponding to a small dot will not start until later than the impulse sent by a large dot, as the small dot does not extend as far in front of the theoretical dot center as does a large dot. The diaphragms "A, B and C each make a complete revolution duringthe time occupied by the drum 54 in moving adistance equal to the distance be tween the centers, of two successive dots, so that if the diaphragms leaveno opening at the center of one dot, they will have returned to that position of no opening at the center of the next dot. If it be supposed that a dot of considerable size isnow being sent,

it will be seen that the circuit 33 will remain closed longer than in the-case of the sending of a small dot, and also that this closure will come earlier and extend later; thus, at

the beginning of the impulse, the diaphragms of asize corresponding to that of the sending half-tone dot, the impulse will cease and the mirror 86 will throw the beam of light away from the aperture so'that the exposure will cometo an. end. A photographic record will thus be produced upon the film 38 exactly proportional in size to the area of the sending half-tone dot. The reason for having one of the diaphragms stationary, as shown at D, is that'the rotation of the drum carrying the film 54, continually exposes past the edge of this diaphragm a fresh film surface, producing the same effect as if the film were stationary and the. diaphragm D moved relatively to it.'

It is obvious that the forms and propor for forming the aperture for admitting light to the recording sensitized film, including the degree of eccentricity of the mov-- able diaphragms, may be varied to produce an aperture of desired shape, usually such an aperture as will produce a substantially square dot upon the film. The portions of the diaphragms arc preferably'such that all of the dots produced will be symmetrical in outline regardless of their size.

I do not limit myself to the particular number of diaphragms shown, as the same or a similar result may be obtained by the use of modified apparatus such as an arrangement of two diaphragms which engage or overlap each other, each of the diaphragms being provided with a row of graded holes. Such a construction is illustrated diagrammatically in Fig. 9, in whicha pair of-diaphragms 100 and 101 are pro-- vided which rotate ,in opposite directions about the'axes 102 and 103, respectively, these two diaphragms overlapping and being provided with rows of graduated holes,

104;. The diaphragms rotate in the direction of the arrows, and, at the same time, speed so that an aperture 105 will be formed by the registration of corresponding holes in two diaphragms. The smallest holes register first, and, as the diaphragms revolve, successively larger holes come into registration so that the eflect of an aperture gradually increasing in size is produced. These dlaphragms are placed 1n the same relation to the source of light and sensitized surface as the diaphragms A B C and D shown in Fig. 5, and the operation is essentially the same. It is also obvious that I may make a variety of other changes and modifications in the specific apparatus shown: for instance, I may use in place of the oscillating mirror a shutter for control-- ling the admission .of light to the sensitized recording sur ace.

In Fig. 10 ,have shown a modified construction in which ashutter is utilized in place of the oscillating mirror. This figure shows the four diaphragms A, B,'C' and D forming the aperture between them, the

diaphragm B being provided with an extension 106 which acts to cover the aperture which would otherwise be formed between the diaphragms during the time that such aperture is decreasing from maximum to zero. In other words, the aperture starts from zero and increases to maximum and is then closed during the other half revolution of the diaphragms. The shutter for cutting off the light from the aperture is indicated at 107, it being preferably mounted upon the end of arm 108 pivoted at 109.

g The arm carries the armature 110 which is adapted to be acted upon by the magnet to throw the beam of light 111 during the time that the impulse is coming over the line so as to permit the light to pass through the aperture and make a record of the impulse. When the impulse ceases and the magnet 111- is denergized, the shutter is released and is. quickly drawn into a position to close the aperture by the spring 112. In order to restore the shutter to such a position that the armature 110 will be within the influence of the magnet 111, a cam 113 is used, this cam bein mounted upon a shaft of the disk B an acting upon the stop 114on the shutter arm in such a way as to'push the shutter open and bring the armature into proximity with the magnet. This is accomplished during the time that the aperture is closedby the extension 106, so that the exposure of the sensitized surface through the aperture is not affected. At the same time that the minimum aperture is opened between the diaphragms and by the movement of the extension 106 beyond the limit of the aper-.

ture, the shutter is restored. to its open position with the armature adjacent to the magnet so that any impulse energizing the upon the arm and retain the as shown in Fig. 10. This condition continues so long as the impulse -lasts, but as the cam 113 is now moved out of the way of "the stop 114, as soon as the impulse ceases the shutter will close and cut ofi the light.

As will be apparent, I may produce at the receiving apparatus a picture which is a negative of the picture at the sending apparatus, that is, having a dot or exposed portion corresponding to every transparent dot.

of the sending half-tone, or I may make the record identical with the sending picture by changing the position of the mirror or shut ter and the operating mechanism therefor so that the light will'be cut 011' from the receiving surface. at the times when the circuit is closed instead of when it is interrupted. Such an arrangement is illustrated in Fig. 11 in which the mirroris. arranged through the aperture and upon the sensitized surface when the line is denergized, while, when the impulse is upon the line and the armature contracted by the magnet, the mirror will be tilted so as tothrow'the beam away from the aperture, ted=line 120.

The words half-tone and half-tone negative? are used herein for the sake of clear expression, but I do not intend thereby to limit myself to the use of the articles technically known by those names.

Having described my invention, I claim! 1. In apparatus of the class described, a sending apparatus, and a receiving apparatus, said sending apparatus comprising as indicated by the dot-.

means for sending a series of impulses'to said receiving apparatus, the lengths of said impulses corresponding to the tones of ortions of a picture, sald receiving mac ine comprising a photo-sensitive surface; means controlled .,by said impulses for exposing successive ortions of said surface to light, the light to which said surface is exposed passing through annperture, and means for continually and gradually varying the area of said aperture between maximum and minimum values.

2. In a machinedor photographically reproducing at a distance half tones'by the operation of electrical impulses caused by and corresponding in relative frequency and duration to the dots of such half .tones, a series of eccentricallyl mounted diaphra whose edges mutua y engage each ot er,

which move at uniform speed, so that an aperture is constantly formed which increases steadily in size from. zero to a fixed maximum and then at the same rate becomes zero again; and a means for admitting light through said aperture by the operation of a shutter or mirror which is caused to oscillate so that thereare photogr P ings, said diaphragms opening and closing 1 by the several electrical impulses aforesaid, ically produced on a moving sensitized surface to which these operations admit the light, dots which correspond in size and relative location'to the dots of the half tone which is being transmitted.

3. In a machine for photogrsphically reproducing, from electrical imp ses derived rom and related to each other as the dots of a half tone; dots corresponding in size and relative situation to the dots of the transmitted half tone, four circular diaphragms which engage each other, one of which is, fixed,

the other three of which move 'at uniform speed'on eccentric bearan aperture having four equal slightly concave sides; in combination with. a means actuated by the electric impulses produced from the original half tone, for permitting light to pass to a moving sensitized surface beyond the opening made posures being governed in by the movmg diaphragms aforesaid. v

4. In atelegraphic sending instrument, a selenium cell, means to; intermittently exposing a portion of saldcell to light at -a. xed point, the duration 6f successive ex-v the intervals between said ex-- accordance with to be transmitted, anelectric' posures and of the impulse circuit adapted to be closed through a portion of the selenium f said celiyan d means. for moving said cel progressively-to cause a previously unexposed portion of/sel'enium to replace that just exposed at said point of illumination. I

5- In -a telegraphic sending instrument, a

' is altered by exposure selenium cell, means for intermittently exiplosing' a' portion of said cell to light at a xed .point, the duration of successiveexposures and of the intervals between said exposures being governed in accordance with the impulse to be transmitted, an electric circuit adapted to be closed through a portion of the selenium of said cell, means for movingsaid cell progressively tocause a previously to replace that just exposed in from said "circuit the portion of the se enium whichis replaced.

6. In combination with anelectric circuit and a controlled source of light, a selenium cell comprising a selenium element, means unexposed portion of selenium at said point of illumination and simultaneously withdrawfor moving the same across the field'of illumination whereby successive portions of the selenium element are exposed, and means vfor simultaneously withdrawing from the circuit that portion of the selenium ele I ment exposed at the point of illumination durinlgn the immediately preceding impulse.

7.: a selenium circuit closing device, a pair of contact brushes, a ring of selenium supported in contact with said brushes, and means for rotating, said rin that portion only of said ring which lies between the edges of said contact brushes being capable of exposure to light. 7

8. In a telegraphic circuit, a receiving device sensitive to changes in currentfintensity, and a sending device including an endless surface of material whose specific resistance is altered by exposure to light, and means for introducing a different porportion of said surface into the'circuitv at" each impulse originated therein and for removing from the said circuit the portion of said surface active during the'immediately c resistance ,only'that portion of said surface which sponding in relative freiuency and duration to the dots of a hal -tone, a. series of eccentrically moulit'ed diaphragms with mutually engaging edges, means for moving said diaphragms at a uniform speed to form an aperture constantly alterin its area from zero to a fixed maximum an returning at the same rate'to zero, and means for illumi nating said aperture at controlled intervals to forma, photographic i-ecord comprising York; this .four th -dey of November, one dots exactly corresponding in proportionthousand ,nine' hundredand eight.

ality and proportional location to the dots I ELIOT KEEN. of the half-tone originating the impulse; Witnesses: 1 -5 Signed at the city of New .York, in the Tnos. JACQUES, Jr.,

county of New York and State of New I ERGAR 

